The present invention relates generally to an improved composition and method for the quantitative determination of phospholipids in a sample. More specifically, the invention is concerned with a diagnostic agent useful in the quantitative determination of phospholipids in blood serum.
Phospholipids are found in serum, egg, meat, vegetables and the like. It is important to determine the phospholipid content in such substances for diagnosing disease, dietetics, etc. In this regard, medical science has recognized the usefulness of determining the content of phospholipids in blood serum as an aid in diagnosing disease such as hypercholesteremia, liver disease and the like.
A number of tests, techniques and methods have been proposed and are being used to measure or estimate the amount of phospholids in the blood. Among the known methods, more widely used conventional methods are colorimetric procedures utilizing molybdate. Some of these procedures depend upon the conversion of phospholipid to inorganic phosphorous by incinerating a sample; reacting the phosphorous with molybdate to form a phosphomolybdic acid; reducing the phosphomolybdic acid with a reducing agent to form molybdenum blue; and measuring the absorption color of the molybdenum blue. [J. Lah. Clin. Med. Vol. 35, 155 (1950); J. Biol. Chem. Vol. 234, 466 (1959); Shinryo Vol. 16, 677 (1963); Rinsho Byori Vol. 10, 194 (1962), ibid. Vol. 15, 853 (1967)].
More recently, a method has been proposed which contemplates the enzymatic conversion of the phospholipids present in the blood specimen to phosphoric acid and the measurement of the color of the reaction solution obtained by reacting the phosphoric acid with molybdate and then reducing the resultant mixture (Yatron Document RM 137-K, Yatron Co., Ltd.).
The known methods for the quantitative determination of phosphlipids suffer from one or more of the disadvantages of requiring highly skilled laboratory techniques, requiring a great deal of time to perform, not giving consistently precise results and requiring blank measurments owing to interference of the phosphorous contained in the sample and vessels.